Uniden DSS8900 Series Owner's Manual page 11

If two letters in a row use the same number key, enter the first
letter, then use [right] on the four-way function key to move the
cursor to the next position to enter the second letter.
For example, to enter the word "Movies":
1) Press [6] once to enter M.
2) Use [right] on the four-way function key to move the cursor
to the right.
3) Press [6] six times to enter o.
4) Press [8] six times to enter v.
5) Press [4] six times to enter i.
6) Press [3] five times to enter e.
7) Press [7] eight times to enter s.
8) Press [menu/select] to end your text entry.
If you make a mistake while entering a name, use [right] or [left]
on the four-way function key to move the cursor to the incorrect
character. Press [clear/int'com] to erase the wrong character,
and then enter the correct character. To delete all characters,
press and hold [clear/int'com].
Number of times key is pressed
10